Window opening control devices are devices that restrict the size of the open area of a window so that it is too small for a young child (e.g., five years of age or younger) to fall through. Specifically, window opening control devices allow the window opening to be set at a predetermined position.
For instance, the United States Consumer Product Safety Commission (CPSC) has advised caregivers to open windows less than four inches when a young child is present. Similarly, the American Society of Testing and Materials' (ASTM) Standard Specification for Window Fall Prevention Devices With Emergency Escape (Egress) Release Mechanisms (ASTM Designation F2090-10) specifies that “no space shall exist at the lowest opening portion of the window opening, that would permit the passage of a rigid sphere measuring 4.0 in. (102 mm) in diameter (Section 5.1.1, supra). However, the window may be opened further with an additional operation such as an operation performed using a key, a tool, or special knowledge.
Although numerous window opening control devices have been developed for double hung and slider type windows, no such devices have been widely disseminated for use with casement style windows (i.e., windows that are attached to their frames by one or more hinges).